1. Field of the Invention
The present invention relates to a balancer of a washing machine, and, more particularly, to a balancer of a washing machine comprising a plurality of baffles, having different heights, alternately disposed in the balancer, thereby reducing further vibration and noise generated due to the balancer during a spin-drying operation of the washing machine.
2. Description of the Related Art
Generally, a washing machine is a machine that removes contaminant from laundry, such as clothes or bedclothes, using emulsification of detergent, friction of water stream generated by the rotation of washing blades, and impact applied to the laundry by the washing blades.
FIG. 1 is a sectional view illustrating a conventional washing machine, FIG. 2 is a perspective view, partially cutaway, illustrating a drum of the conventional washing machine, and FIG. 3 is a sectional view taken along line A-A′ of FIG. 2, illustrating the drum of the conventional washing machine rotated at high speed during a spin-drying operation.
Referring to FIG. 1, the conventional washing machine comprises: a casing 10 forming the outer appearance of the washing machine; a tub 14 mounted in the casing 10 in a shock-absorbing fashion; a drum 18 rotatably disposed in the tub 14 for receiving laundry; and a motor unit 20 mounted at one side of the tub 14 for rotating the drum 18.
At the front surface of the casing 10 is hingedly mounted a door 12, by which the laundry is put into the drum 18 when the door 12 is opened. Between the front surface of the casing 10 around the door 12 and the front surface of the tub 14 is disposed a gasket 17 for sealing a space defined between the inside surface of the casing 10 and the front surface of the tub 14, and therefore, preventing leakage of washing water.
The washing machine further comprises: springs 11 connected between the top surface of the casing 10 and the drum 18 for supporting the tub 14 such that the tub 14 can be suspended from the upper end of the casing 10; and a damper 13 connected between the tub 14 and the bottom surface of the casing 10 for supporting the tub 14 in a shock-absorbing fashion.
The washing machine further comprises a balancer 15. As shown in FIG. 2, the balancer 15 comprises: a balancer ring 21 attached to the front surface of the drum 18 in the circumferential direction, the balancer ring 21 containing salt water; a plurality of partitions 23 for partitioning the balancer ring 21 in the radial direction; and a plurality of baffles 25 radially attached to the balancer ring 21 while being spaced apart from the balancer ring 21 by side gaps 27, the baffles 25 having a predetermined height.
Specifically, the baffles 25 have the same height. Also, the baffles 25 are spaced apart from the respective neighboring partitions 23 by predetermined upper gaps 29.
Now, the operation of the conventional washing machine with the above-stated construction will be described.
When a user puts laundry into the drum 18, closes the door 12, and operates the washing machine, detergent and washing water are supplied into the drum 18, and the drum 18 is rotated by the motor unit 20.
As the drum 18 is rotated, the laundry is lifted by lifters 19 attached to the inside surface of the drum 18 and then falls from the lifters 19. In this way, a washing operation of the laundry is performed.
After the washing operation is completed, a rinsing operation is performed for rinsing out bubbles from the washed laundry. After the rinsing operation is completed, a spin-drying operation is performed for removing moisture from the rinsed laundry.
While the drum 18 is rotated at high speed during the spin-drying operation, the moisture is centrifugally removed from the laundry. The removed moisture is discharged out of the drum 18 through through-holes of the drum 18, and is then drained out of the washing machine.
The rotating speed of the drum 18 is gradually increased from standstill of the drum 18. When the drum 18 is rotated at low speed, salt water flows through the side gaps 27 between the baffles 25 and the balancer ring 21 as well as the upper gaps 29. As a result, the salt water is gathered at the lower part of the balancer due to gravity.
As the rotating speed of the drum 18 is increased, a centrifugal force, which is greater than the gravity applied to the salt water, is generated. As a result, the salt water is raised by the rotation of the drum 18, and therefore, the salt water is dispersed in the circumferential direction, as shown in FIG. 3.
Specifically, the salt water is filled in the respective independent spaces defined by the partitions 23 up to the height lower than that of the baffles 25. Under this condition, the normal spin-drying operation of the washing machine is performed.
During the normal spin-drying operation, the laundry is eccentrically placed in the drum 18, and as a result, the drum 18 suffers from unbalanced mass distribution. At this time, the salt water in the balancer is moved in the direction opposite to the eccentric direction caused due to the unbalanced mass distribution such that the unbalanced mass distribution is compensated for.
However, the conventional washing machine has the following problems. As the rotating speed of the drum 18 is increased during the normal spin-drying operation, the vibration frequency of the drum 18 is coincident with that of the tub 14. At this time, a resonance phenomenon, which causes vibration and noise, is generated, or other abnormal vibration may be generated. As a result, the salt water is surged in the spaces between the respective baffles 25 and the neighboring baffles 25, and therefore, vibration and noise are increased.